Grinders for grinding hay or other materials to be ground are shown in U.S. Pat. No. 3,912,175 to Anderson, U.S. Pat. No. 3,966,128 to Anderson et al., U.S. Pat. No. 4,033,515 to Barcell et al., U.S. Pat. No. 4,134,554 to Morlock, U.S. Pat. No. 4,210,289 to Arnoldy, U.S. Pat. No. 4,846,411 to Herron et al., U.S. Pat. No. 5,419,502 to Morey, U.S. Pat. No. 5,626,298 to Arnoldy, and U.S. Pat. No. 6,412,715 to Brand et al., all of which are incorporated herein by reference in their entirety.
Tub grinders are used to reduce the size of many things such as bales of hay, tree branches, material from demolished buildings, etc. The material is placed in the top of the “tub” portion, for example with a grappling hook or front end loader on a tractor, then the tub portion rotates around a floor as can be seen in the prior art shown in FIG. 1 of the drawings. An opening in the floor as shown in prior art FIGS. 1 and 2 is provided with rotating hammers passing between slug bars, the hammers hitting the material in the tub, reducing the size to smaller particles that are delivered to an unloading conveyor to put the ground up particles in a pile or on a trailer or the like for transporting the ground material to another place. Typically the material to be ground is moving in the direction of the tub as shown by the arrow in FIG. 1, while the hammers are rotating in the direction shown in FIG. 1.
One of the problems associated with tub grinders is that they do not operate at optimum efficiency for all types of material to be ground.
Accordingly a tub grinder that can be easily adapted to efficiently grind different types of material is needed.
Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. Certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. The terms and expressions used herein have the ordinary technical meaning as is accorded to such terms and expressions by persons skilled in the technical field as set forth above except where different specific meanings have otherwise been set forth herein.